Mask plate and method for manufacturing the same

ABSTRACT

A mask plate and a method for manufacturing the same are provided. The mask plate comprises a first sub-mask plate and a second sub-mask plate stacked with each other, the first sub-mask plate is provided with at least one first opening therein, a size and a shape of the first opening correspond to those of a target display panel; the second sub-mask plate is provided with a second opening region, which covers at least one of the at least one first opening and includes a plurality of second openings. Since it is only required to ensure that the sizes and shapes of the first openings are the same as those of the target display panels respectively, and it is unnecessary to further manufacture openings for forming pixel patterns, comparing with the existing mask plate, the manufacturing process of the present disclosure is more simple and the manufacturing cost is lower.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority to Chinese Patent ApplicationNo. 201620661367.2 filed on Jun. 29, 2016, entitled “MASK PLATE”, thedisclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to a field of vacuum evaporationtechnology for OLED, and particularly relates to a mask plate and amethod for manufacturing the same.

BACKGROUND ART

In Organic Light-Emitting Diode (OLED) technology, a vacuum evaporationprocess is an important process for manufacturing an OLED, and a maskplate is a key member in the vacuum evaporation process. The mask platehas a plurality of openings arranged in a matrix manner for formingpixel patterns on display panels located on a backboard glass by usingevaporation materials. The plurality of openings form a plurality ofopening regions, shapes and sizes of the opening regions are the same asthose of the display panels on the backboard glass, and the openingregions are distributed in a same manner as that of the display panelson the backboard glass. As rapid development of the display industry andthe diversity of people's requirements, the shape of the display panelin the field of wearable devices is not limited to the traditionalrectangle, but can be circular or irregular shape with a sense ofdesign.

The existing mask plate is of a single-layered structure, openingregions in the mask plate correspond to shapes and sizes of the targetdisplay panels, therefore, in a case of manufacturing display panelswith different shapes and sizes, it is required to use various maskplates. Accordingly, it is necessary to manufacture mask plates withvarious shapes and sizes. Since a process for manufacturing openings inthe mask plate for forming the pixel patterns is complicated, and itrequires a high manufacturing accuracy, thus resulting in a highmanufacturing cost of the mask plate.

Therefore, a new type of mask plate is needed.

SUMMARY

An object of the present application is to provide a mask plate, whichcan reduce the manufacturing cost.

In an aspect, there is provided a mask plate comprising a first sub-maskplate and a second sub-mask plate stacked with each other, wherein thefirst sub-mask plate is provided with at least one first opening providetherein, and a size and a shape of the first opening correspond to thoseof a target display panel; the second sub-mask plate is provided with asecond opening region, which covers at least one of the at least onefirst opening and includes a plurality of second openings.

Optionally, the shape of the first opening is the same as that of thetarget display panel, and an area of the first opening is larger thanthat of the target display panel.

Optionally, a distance from an edge of an orthographic projection of thefirst opening on a backboard glass to a closest edge of the targetdisplay panel on the backboard glass corresponding to the first openingranges from 75 μm to 150 μm.

Optionally, a shape of the second opening region is a rectangle.

Optionally, the second sub-mask plate is provided with a plurality ofsecond opening regions, and shapes of the second opening regions are thesame with each other.

Optionally, sizes of the second opening regions are the same with eachother.

Optionally, the second sub-mask plate is stacked on the first sub-maskplate.

Optionally, outline dimensions of the first sub-mask plate and thesecond sub-mask plate are the same with each other, and shapes of thefirst sub-mask plate and the second sub-mask plate are the same witheach other.

Optionally, the second sub-mask plate includes a plurality of parts withthe same shapes and the same sizes, and the plurality of parts arespliced together to form the second sub-mask plate.

Furthermore, the mask plate further comprises a frame, wherein the firstsub-mask plate is welded to the frame through first weld spots, theparts forming the second sub-mask plate are welded to the first sub-maskplate through second weld spots.

Optionally, a distance between the first weld spot and the second weldspot closest thereto is larger than 2 mm.

Optionally, the first weld spots are arranged at positions on aperiphery of the first sub-mask plate, the second weld spots arearranged at first sides and second sides of the parts forming the secondsub-mask plate, and wherein the first sides and the second sides aresides of the parts of the second sub-mask plate, which are not used forsplicing.

Optionally, the first sub-mask plate and the second sub-mask platecomprise metal-invar alloy material.

Optionally, a thickness of the first sub-mask plate ranges from 100 μmto 150 μm, and a thickness of the second sub-mask plate ranges from 20μm to 40 μm.

In another aspect, there is provided a method for manufacturing maskplate comprising steps of:

forming a first sub-mask plate, wherein the first sub-mask plate isprovided with at least one first opening therein, and a size and a shapeof the first opening correspond to those of a target display panel;

forming a second sub-mask plate, wherein the second sub-mask plate isprovided with a second opening region therein, the second opening regioncovers at least one of the at least one first opening and includes aplurality of second openings;

bonding the first sub-mask plate to a frame; and

bonding the second sub-mask plate to the first sub-mask plate.

Optionally, bonding the first sub-mask plate to the frame furthercomprises: welding the first sub-mask plate to the frame, and

bonding the second sub-mask plate to the first sub-mask plate comprises:aligning the second sub-mask plate to the first sub-mask plate; andwelding the second sub-mask plate to the first sub-mask plate.

Optionally, aligning the second sub-mask plate to the first sub-maskplate further comprises: aligning first alignment holes at edges andcorners of the first opening in the first sub-mask plate to secondalignment holes in the second opening region of the second sub-maskplate.

Optionally, forming the second sub-mask plate further comprises:splicing a plurality of parts with same sizes and same shapes togetherto form the second sub-mask plate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a structural diagram of a backboard glass in an embodiment ofthe present application;

FIG. 1b is a structural diagram of a mask plate in an embodiment of thepresent application;

FIG. 2 shows a projection relationship between a first opening and adisplay panel according to an embodiment of the present application;

FIG. 3 is a structural diagram of a mask plate in an embodiment of thepresent application;

FIG. 4 is a structural diagram of a mask plate in an embodiment of thepresent application;

FIG. 5 is a flow chart of a method for manufacturing a mask plateaccording to an embodiment of the present application.

REFERENCE NUMERALS

1—first sub-mask plate; 2—second sub-mask plate; 3—backboard glass;4—frame; 11—first opening; 12—shielding region; 13—first weld spot;21—second opening region; 22—strip part; 23—second weld spot; 31—displaypanel; 211—second opening; 231—first side; 232—second side.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In order to make a person skilled in the art better understand solutionsof the present application, the present application will be described indetail below in conjunction with the accompanying drawings andimplementations.

As shown in FIG. 1a , a backboard glass 3 includes a plurality of targetdisplay panels 31, and the present embodiment is explained by taking adisplay panel 31 with a circle shape as an example. It should be notedthat the backboard glass 3 may include only one target display panel 31.

As shown in FIG. 1b , the present application provides a mask platecomprising a first sub-mask plate 1 and a second sub-mask plate 2stacked with the first sub-mask plate 1, wherein the first sub-maskplate 1 is provided with at least one first opening 11 therein, and aregion of the first sub-mask plate 1 other than the first opening 11 isa shielding region 12. A size and a shape of the first opening 11 arerespectively the same as those of the target display panel 31 on thebackboard glass 3, that is, the first opening 11 corresponds to thetarget display panel 31. The second sub-mask plate 2 is provided with atleast one second opening region 21 therein, and the second openingregion 21 covers at least one of the at least one first opening 11. Thesecond opening region 21 includes a plurality of second openings 211,which are provided in a matrix manner and correspond to pixels so thatthey are used for forming pixel patterns.

The mask plate in the present embodiment is of a two-layered structure,and comprises the first sub-mask plate 1 and the second sub-mask plate 2which are stacked with each other, the first sub-mask plate 1 isprovided with at least one first opening 11, the size and the shape ofwhich are respectively the same as those of the target display panel 31.The second sub-mask plate 2 is provided with the second opening region21 therein, a plurality of second openings 211 for forming pixelpatterns are provided in a matrix manner in the second opening region21, and the second opening region 21 covers at least one of the at leastone first opening 11. In a case of manufacturing target display panels31 with different shapes and sizes are to be manufactured, it is onlyrequired to configure the first openings 11 in the first sub-mask plate1 so that the first openings 11 have the same sizes and shapes as thetarget display panels 31 respectively, and by assembling the firstsub-mask plate 1 with the existing second sub-mask plate 2, a new maskplate is formed. Since it is only required to ensure that the sizes andshapes of the first openings 11 are the same as those of the targetdisplay panels 31 respectively, and it is unnecessary to furthermanufacture openings for forming pixel patterns, therefore, comparingwith the existing mask plate, the manufacturing process of the maskplate according to the present disclosure is more simple and themanufacturing cost is lower.

In a practical application, as shown in FIG. 1b , an area of the firstopening 11 may be slightly larger than that of the target display panel31. In this case, in a process of tension and stretch of the mask plate,even the size and shape of the first opening 11 change, the problem thatevaporation material cannot be evaporated on the target display panel 31will not occur.

Optionally, a distance between an edge of an orthographic projection ofthe first opening 11 on the backboard glass 3 and a closest edge of acorresponding target display panel 31 on the backboard glass 3 rangesfrom 75 μm to 150 μm. The present embodiment will be explained by takingthe display panel 31 and the first opening 11 are of circle shapes as anexample. As shown in FIG. 2, a distance h1 between the edge of theorthographic projection of the first opening 11 on the backboard glass 3and the closest edge of the corresponding target display panel 31 on thebackboard glass 3 ranges from 75 μm to 150 μm, that is, a diameter D2 ofthe first opening 11 is larger than a diameter D1 of the target displaypanel 31 by 150-300 μm.

The second opening region 21 may be of a circle shape, a rectangleshape, a polygon shape and so on. Optionally, the second opening region21 may be of a rectangle shape, thus in the process of tension andstretch of the mask plate, comparing with the second opening region 21of non-rectangle shape, the second opening region 21 of rectangle shapemay have uniform stress strain, therefore, wrinkles can be preventedfrom occurring in the second mask plate 2, avoiding the defect of colormixing of the display panel after the evaporation process.

As shown in FIG. 1b , in a case that the first sub-mask plate 1 isprovided with a plurality of first openings 11 therein, and the secondsub-mask plate 2 is provided with a plurality of second opening regions21 therein, shapes of the second opening regions 21 in the secondsub-mask plate 2 may be not limited to the shapes, arrangement,distribution of the display panels 31 and the circuits at the frame. Aslong as the second opening regions 21 have the same shapes, in theprocess of tension and stretch of the mask plate, the second openingregions 21 may have uniform stress strain, thus no wrinkle will occur inthe second sub-mask plate 2. Accordingly, the second openings 211 in thesecond opening regions 21 may generate the same deformation, thus pixelpatterns formed through the second openings 211 have the same sizes andshapes, therefore, the problem of defect of color mixing of the displaypanel after the evaporation process can be solved.

Optionally, sizes of the second opening regions 21 are the same witheach other, thus in the process of tension and stretch of the maskplate, the second opening regions 21 with the same shapes and sizes mayhave more uniform stress strain.

As shown in FIG. 1b , the second sub-mask plate 2 is stacked on thefirst sub-mask plate 1, the evaporation process is performed in an orderfrom the second sub-mask plate 2 to the first sub-mask plate 1. A gapexists between the first sub-mask plate 1 and the second sub-mask plate2 and the evaporation material may be diffused between the firstsub-mask plate 1 and the second sub-mask plate 2. The evaporationmaterial first passes through the second openings 211 in the secondopening regions 21 of the second sub-mask plate 2 and diffuses, and thenpasses through the first openings 11 in the first sub-mask plate 1 andis evaporated onto the display panels 31. Since the first sub-mask plate1 is under the second sub-mask plate 2, the shielding region 12 of thefirst sub-mask plate 1 may block the evaporation material, therefore,the evaporation material cannot be evaporated onto a region other thanthe display panels 31.

Optionally, the first sub-mask plate 1 and the second sub-mask plate 2may have the same outline dimensions and shapes.

The second opening region 21 may cover one or more first openings 11,for example, the second opening region 21 may cover two first openings11 or four first openings 11. In the present embodiment, as shown inFIG. 1b , the second opening region 21 covers four first openings 11.

As shown in FIG. 3, the first sub-mask plate 1 is of an integrationstructure, and the second sub-mask plate 2 may include a plurality ofparts with the same shapes and sizes, which are spliced together to formthe second sub-mask plate 2. In the embodiment, the parts forming thesecond sub-mask plate 2 are of strip shapes, a size and a shape of thesecond sub-mask plate 2 formed by splicing the strip parts 22 may be thesame as the outline dimension and shape of the backboard glass. Thepresent embodiment will be described by taking the second sub-mask plate2 including four strip parts 22 as an example. In the process of tensionand stretch of the mask plate, the strip parts 22 may uniformly bear thestress applied to the second sub-mask plate 2, so that the stressstrains of the strip parts 22 are more uniform, further ensuring thatthe defect of color mixing of the display after the evaporation processwill not occur.

It should be noted that first alignment holes (not shown in drawings)are provided at edges and corners of the first openings 11 in the firstsub-mask plate 1, and second alignment holes (not shown in drawings) areprovided at positions in the second opening regions 21 of the secondsub-mask plate 2 corresponding to the edges and corners of the firstopenings 11, by aligning the first alignment holes and the secondalignment holes, the first sub-mask plate 1 and the second sub-maskplate 2 may be accurately aligned.

As shown in FIG. 4, the mask plate in the embodiment may furthercomprise a frame 4, the first sub-mask plate 1 is welded to the framethrough first weld spots 13, the strip parts 22 forming the secondsub-mask plate 2 are welded to the first sub-mask plate 1 through secondweld spots 23. As such, even in a case that the first sub-mask plate 1is welded to the frame 4 by error, during a new weld for repairing, itis unnecessary to repair the weld positions of the strip parts 22, thusremarkably increasing the repairing efficiency.

Optionally, as shown in FIG. 4, a distance h2 between the first weldspot 13 and the second weld spot 23 closest thereto is larger than 2 mm,which can facilitate welding and avoid errors in welding positions.

The first weld spots 13 are arranged at positions on a periphery of thefirst sub-mask plate 1, the second weld spots 23 are arranged at firstsides 231 and second sides 232 of the parts forming the second sub-maskplate 2. The first side 231 and the second side 232 are sides of thepart 22 of the second sub-mask plate 2 not being adjacent to each other.

Optionally, the first sub-mask plate 1 and the second sub-mask plate 2may comprise metal-invar alloy material.

Optionally, a thickness of the first sub-mask plate 1 ranges from 100 μmto 150 μm, and a thickness of the second sub-mask plate 2 ranges from 20μm to 40 μm.

FIG. 5 is a flow chart of a method for manufacturing a mask plateaccording to an embodiment of the present application. As shown in FIG.5, the method for manufacturing the above mentioned mask platecomprises:

Step S501, forming a first sub-mask plate, wherein the first sub-maskplate is provided with at least one first openings therein, and a sizeand a shape of the first opening correspond to those of a target displaypanel;

Step S502, forming a second sub-mask plate, wherein the second sub-maskplate is provided with a second opening region therein, the secondopening region covers at least one of the at least one first opening andincludes a plurality of second openings;

Step S503, bonding the first sub-mask plate to a frame; and

Step S504, bonding the second sub-mask plate to the first sub-maskplate.

The step S503 further comprises: welding the first sub-mask plate to theframe.

The step S504 further comprises: aligning the second sub-mask plate tothe first sub-mask plate; and

welding the second sub-mask plate to the first sub-mask plate.

Optionally, the step S504 further comprises: aligning first alignmentholes at edges and corners of the first openings in the first sub-maskplate to second alignment holes within the second opening regions of thesecond sub-mask plate.

Optionally, the step S502 further comprises: splicing a plurality ofparts with same sizes and same shapes together to form the secondsub-mask plate.

Hereinafter, a method for assembling the first sub-mask plate and thesecond sub-mask plate in the method for manufacturing the above maskplate will be described below in conjunction with FIG. 4.

First, a stretching machine (not shown in drawings) is used to stretchthe first sub-mask plate 1, after a position of the first sub-mask plate1 is fixed through the first alignment holes, the first sub-mask plate 1is welded to the frame 4 through the first weld spots 13, wherein adroop amount of the first sub-mask plate 1 is less than 150 μm. Then thestrip parts 22 forming the second sub-mask plate 2 are stretched, afterpositions of the strip parts 22 are fixed through the second alignmentholes, the strip parts 22 forming the second sub-mask plate 2 are weldedto the first sub-mask plate 1 through the second weld spots 23, thusassembling of the whole mask plate is completed.

Manufacturing a display panel of circle shape has a high demand on themask plate, the mask plate in the embodiment corresponds to thebackboard glass completely, and the first sub-mask plate is used incooperation with the second sub-mask plate, so that limitation of theperiphery circuit of the display panel and the evaporation process tothe design of the mask plate can be reduced, therefore the mask platemay be manufactured according to an optimal design. The mask plate inthe embodiment can not only be used to manufacture a display panel ofnon-traditional rectangular shape such as a circular shape, but alsoreduce the defects caused by the mask plate so as to improve the yieldof the products.

The above embodiment may have following advantages.

The mask plate in the above embodiment is of a two-layered structure,and comprises a first sub-mask plate and a second sub-mask plate whichare stacked with each other, the first sub-mask plate is provided withat least one first opening, a size and shape of which are the same asthose of the a target display panel. The second sub-mask plate isprovided at least one second opening region therein, a plurality ofsecond openings for forming pixel patterns are provided in a matrixmanner in the second opening region, and the second opening regioncovers at least one of the at least one first opening. In a case ofmanufacturing target display panels with different shapes and sizes, itis only required to configure the first openings of the first sub-maskplate to respectively have the same sizes and same shapes as the targetdisplay panels respectively, and by assembling the first sub-mask platewith the existing second sub-mask plate, a new mask plate is formed.Since during manufacturing the mask plate, it is only required to ensurethat the sizes and shapes of the first openings are respectively thesame as those of the target display panels respectively, and it isunnecessary to further manufacture openings for forming pixel patterns,therefore, comparing with the existing mask plate, the manufacturingprocess according to the present disclosure is more simple and themanufacturing cost is lower.

It should be understood that, the foregoing embodiments are onlyexemplary embodiments used for explaining the principle of the presentinvention, but the present invention is not limited thereto. Variousvariations and improvements may be made by a person skilled in the artwithout departing from the protection scope of the present invention,and these variations and improvements also fall into the protectionscope of the present invention.

The invention claimed is:
 1. A mask plate comprising a first sub-maskplate and a second sub-mask plate stacked with each other, wherein thefirst sub-mask plate is provided with a plurality of first openingstherein, a shape of each of the plurality of first openings are the sameas those of a target display panel; the second sub-mask plate isprovided with a plurality of second opening regions, each of whichcovers a plurality of first openings and comprises a plurality of secondopenings; the second sub-mask plate comprises a plurality of parts eachwith a same strip shape and a same size, the plurality of parts areseparate and spliced together to form the second sub-mask plate, each ofthe plurality of parts comprises at least one of the plurality of secondopening regions; each of the plurality of parts is bonded to the firstsub-mask plate at two opposite sides thereof; and first alignment holesare provided at edges and corners of the first openings in the firstsub-mask plate, and second alignment holes are provided at positions inthe second opening regions of the second sub-mask plate corresponding tothe edges and corners of the first openings.
 2. The mask plate of claim1, wherein the shape of the first opening is the same as that of thetarget display panel, and an area of the first opening is larger thanthat of the target display panel.
 3. The mask plate of claim 2, whereina distance from an edge of an orthographic projection of the firstopening on a backboard glass to a closest edge of the target displaypanel on the backboard glass corresponding to the first opening rangesfrom 75 μm to 150 μm.
 4. The mask plate of claim 1, wherein the shape ofeach of the plurality of first openings is circular and a shape of eachof the plurality of second opening regions is a rectangle.
 5. The maskplate of claim 1, wherein the second sub-mask plate is provided with aplurality of second opening regions, and shapes of the second openingregions are the same with each other.
 6. The mask plate of claim 5,wherein sizes of the second opening regions are the same with eachother.
 7. The mask plate of claim 1, wherein the second sub-mask plateis stacked on the first sub-mask plate.
 8. The mask plate of claim 1,wherein outline dimensions of the first sub-mask plate and the secondsub-mask plate are the same with each other, and shapes of the firstsub-mask plate and the second sub-mask plate are the same with eachother.
 9. The mask plate of claim 1, further comprising a frame, whereinthe first sub-mask plate is welded to the frame through first weldspots, the parts forming the second sub-mask plate are welded to thefirst sub-mask plate through second weld spots.
 10. The mask plate ofclaim 9, wherein the first weld spots are arranged at positions on aperiphery of the first sub-mask plate, the second weld spots arearranged at first sides and second sides of the parts forming the secondsub-mask plate, and wherein the first sides and the second sides aresides of the parts of the second sub-mask plate, which are not used forsplicing.
 11. The mask plate of claim 10, wherein a distance between thefirst weld spot and the second weld spot closest to the first weld spotis larger than 2 mm.
 12. The mask plate of claim 1, wherein the firstsub-mask plate and the second sub-mask plate comprise metal-invar alloymaterial.
 13. The mask plate of claim 2, wherein the first sub-maskplate and the second sub-mask plate comprise metal-invar alloy material.14. The mask plate of claim 1, wherein a thickness of the first sub-maskplate ranges from 100 μm to 150 μm, and a thickness of the secondsub-mask plate ranges from 20 μm to 40 μm.
 15. A method formanufacturing mask plate, comprising: forming a first sub-mask plate,wherein the first sub-mask plate is provided with a plurality of firstopenings therein, a shape of each of the plurality of first openings arethe same as those of a target display panel; forming a second sub-maskplate, wherein the second sub-mask plate is provided with a plurality ofsecond opening regions, each of which covers a plurality of firstopenings and comprises a plurality of second openings; bonding the firstsub-mask plate to a frame; and bonding the second sub-mask plate to thefirst sub-mask plate, wherein the second sub-mask plate comprises aplurality of parts each with a same strip shape and a same size, theplurality of parts are separate and spliced together to form the secondsub-mask plate, each of the plurality of parts comprises at least one ofthe plurality of second opening regions; and each of the plurality ofparts is bonded to the first sub-mask plate at two opposite sidesthereof, and wherein first alignment holes are provided at edges andcorners of the first openings in the first sub-mask plate, and secondalignment holes are provided at positions in the second opening regionsof the second sub-mask plate corresponding to the edges and corners ofthe first openings.
 16. The method of claim 15, wherein bonding thefirst sub-mask plate to the frame further comprises: bonding the firstsub-mask plate to the frame, and bonding the second sub-mask plate tothe first sub-mask plate comprises: aligning the second sub-mask plateto the first sub-mask plate; and welding the second sub-mask plate tothe first sub-mask plate.
 17. The method of claim 16, wherein aligningthe second sub-mask plate to the first sub-mask plate further comprises:aligning the first alignment holes at edges and corners of the firstopening in the first sub-mask plate to the second alignment holes in thesecond opening region of the second sub-mask plate.
 18. The method ofclaim 15, wherein forming the second sub-mask plate further comprises:splicing a plurality of parts with same sizes and same shapes togetherto form the second sub-mask plate.
 19. The method of claim 15, whereinthe shape of the first opening is circular and the shape of the secondopening region is a rectangle.